Sentencing of H. Edward Tickel Jr., the former FBI break-in specialist convicted of dealing in stolen diamonds and other offenses, was delayed yesterday after prosecutors told a federal judge of allegations that Tickel revealed national security secrets to a former U.S. Senate aide.

Judge James C. Cacheris of U.S. District Court in Alexandria scheduled a closed-door hearing for May 11 to allow Tickel's defense to respond to the allegations, which were contained in a sealed memo submitted to Cacheris. Tickel has denied the allegations and has not been charged in connection with them.

Cacheris said he will use the memo in deciding whether to revoke Tickel's bond pending any appeal of his conviction in March. Prosecutors have argued for revoking his bond on grounds that he might flee while his case is appealed. Tickel, a 14-year FBI veteran, specialized in secret break-ins known in FBI parlance as "black bag jobs."

Statements at a hearing yesterday indicated that the memo contained allegations by M.J. Probst, a former U.S. Senate aide sentenced last year in a bank robbery and arson scheme, that Tickel revealed secrets to him during a meeting.

Assistant U.S. Attorney John Hume acknowledged in court that Probst might not be viewed as a credible witness but said his statements should be considered by Cacheris in reviewing Tickel's bond status. The nature of the information Tickel allegedly disclosed was not clear from statements heard in the court.

Tickel maintains that federal authorities promised Probst lenient treatment if he would help in a "sting" operation to get Tickel to disclose classified information. Tickel says that he met Probst, an old acquaintance, in the lobby of the Hyatt Regency Hotel in Washington in August 1982, but, Tickel says, he revealed no secrets.

Prosecutors have confirmed that Probst met with Tickel at their request but say the purpose was to discuss the grand jury investigation against Tickel, not classified information. Tickel was convicted last month of six counts of obstructing justice, tax evasion and dealing in allegedly stolen diamonds. He faces up to 35 years in prison and fines totaling $50,000.